The present invention relates to the field of attachment devices and, more particularly, to attachment devices for use in optical systems.
One field in which optical systems play an important role involves the capture of fluorescent signals indicating hybridization of labeled target biological samples with probes on synthesized or spotted probe arrays. Synthesized nucleic acid probe arrays, such as Affymetrix(copyright) GeneChip(copyright) probe arrays from Affymetrix, Inc. of Santa Clara, Calif., have been used to generate unprecedented amounts of information about biological systems. For example, a commercially available GeneChip(copyright) array set is capable of monitoring the expression levels of approximately 6,500 murine genes and expressed sequence tags (EST""s). Experimenters can quickly design follow-on experiments with respect to genes, EST""s, or other biological materials of interest by, for example, producing in their own laboratories microscope slides containing dense spotted arrays of probes using the Affymetrix(copyright) 417(trademark) Arrayer or other spotting devices. Analysis of data from experiments with synthesized and/or spotted arrays may lead to the development of new drugs and new diagnostic tools.
The optical devices used to capture these fluorescent signals from labeled biological samples often are referred to as scanners. Due to the relatively small emission signals sometimes available from the hybridized target-probe pairs, the presence of background fluorescent signals, the high density of the arrays, variations in the responsiveness of various fluorescent labels, and other factors, care must be taken in designing scanners to properly acquire and process the fluorescent signals indicating hybridization. For example, U.S. Pat. No. 6,171,793 to Phillips, et al., hereby incorporated herein in its entirety for all purposes, describes a method for scanning probe arrays to provide data having a dynamic range that exceeds that of the scanner.
Scanners, like other optical systems, generally incorporate a number of mirrors, lenses, and more specialized optical elements that typically are attached to a structure. Various types of conventional devices have been designed to secure these elements to the structure to provide reliable attachment. Conventional attachment devices are described, for example, in P. Yoder, Opto-Mechanical Systems Design (2d ed., Marcel Dekker 1993), and in P. Yoder, Mounting Lenses in Optical Instruments (SPIE Optical Engineering Press 1995), both of which are hereby incorporated herein by reference in their entireties. Nonetheless, there is a continuing need to improve scanner design, and the design of other kinds of optical instruments, to provide more accurate and reliable signals and thus provide experimenters with more sensitive and accurate data.
The optical elements of a scanner may be subject to various forces due to movement of the instrument. There thus is a need for securing those elements without deforming or distorting them or otherwise interfering with their characteristics and operation. Scanners and scanner attachment devices that address these and other needs are described herein with respect to illustrative, non-limiting, implementations.
In some embodiments, not necessarily limited to scanners or optical instruments, an attachment device is described for attaching a part to a structure. The device includes a base and two or more holding elements coupled to the base. The holding elements include a first holding element of a first length and a second holding element of a second length. In some implementations, the second length may be shorter than the first length. Each holding element flexibly engages at least one surface of the part when the device is engaged with the part. The part may, but need not, be an optical element, for example, a mirror, a lens, or a mirror or lens assembly. The base and the holding elements may be formed of a single piece of flexible material.
In some implementations of these embodiments, the attachment device also includes opposing holding elements that are constructed and arranged to rigidly engage opposing side surfaces of the part. Those opposing holding elements may be constructed and arranged, together with the base, to form a substantially flat surface both when the device is engaged with the part and when the device is not engaged with the part. Those opposing holding elements rigidly engage the part, even though they may be made of the same piece of flexible material as are the base and the holding elements that flexibly engage the part. This is so because, in these non-limiting implementations, they lie substantially flat, i.e., are substantially parallel to the base, and are subject to buckling rather than bending or flexing. Thus, the rigidly engaged holding elements resist compression when forces substantially parallel to the base are applied to them. In contrast, the flexibly engaged holding elements form an angle with the flat surface of the base to which they are coupled, and thus flex when a force substantially parallel to the base is applied to them. In various of these implementations, the base has at least two securing elements that secure the device to the structure, each of which may be aligned in proximity to one of the opposing holding elements.
In some implementations, the device is formed from a single piece of flexible material having a substantially flat surface. When disengaged from the part, the device may revert to the substantially flat surface, i.e., it may return to a substantially flat shape. The word xe2x80x9csubstantiallyxe2x80x9d means in the contexts of this and the preceding paragraphs that the device, in the shape from which it is made from the flexible material and the shape it assumes after disengagement from the part, is generally flat but not necessarily perfectly flat. For example, the flexible material from which the device is made may have bumps, waves, burrs, and other irregularities or imperfections such as may be expected, for instance, in typical commercial molding or stamping operations. The device may also be made from flexible material that is not substantially flat, but the device may thereafter be substantially flattened. Also, when the device is disengaged from the part, some portions of the device, such as the holding elements that flexibly engage the part, may not completely return to their original substantially flat state. That is, they may protrude somewhat from the plane of the support regions or of other holding elements due to the less than perfect elasticity of the flexible material. These protrusions may increase in proportion to the number of times the device is engaged and disengaged from a part. However, any such deviations from flatness, either in the original shape of the device or the shape it takes after being disengaged from a part, are incidental and are not related to the functioning of the device.
In various implementations, two or more opposing holding elements exert forces on at least one surface of the part. These forces are due, at least partially, to deformation of the opposing holding elements from the substantially flat surface when the device is engaged with the part. Also, these forces may be due, at least partially, to deformation of a portion of the base from the substantially flat surface when the device is engaged with the part. Each of the forces may include components perpendicular and/or parallel to the substantially flat surface. As used in this context, the word xe2x80x9copposingxe2x80x9d is used broadly to mean that the holding elements may, when engaged with the part, exert partly or wholly opposing forces on the part so as to resist movement. It is therefore not necessary in all implementations that the holding elements be exactly opposite from each other, such as pairs of sides of a square, or even that they be regularly opposed around the part, such as the three sides of an equilateral triangle surrounding the part.
The first and second holding elements may be adjacent or near to each other. In these cases, when the device is engaged with the part, the second holding element may be deformed from the substantially flat surface due, at least in part, to the first holding element being deformed from the substantially flat surface.
In various implementations, the base has at least one securing element that secures the device to the structure. The securing element may be, for example, an aperture for accepting a coupling element, such as a screw or bolt. Alternatively, the securing element may be a bonding element, such as a weld or glue.
With respect to some specific embodiments, a scanner is described that includes an optical element, a support structure, and a device that attaches the optical element to the support structure. The attachment device includes a base having at least one securing element that secures the device to the support structure. The device also includes a plurality of holding elements coupled to the base including a first holding element of a first length and a second holding element of a second length shorter than the first length. Each holding element flexibly engages at least one surface of the optical element when the device is engaged with the optical element.
Also described herein is a device for holding an optical element in a semi-rigid manner. The term xe2x80x9csemi-rigidxe2x80x9d used in this context means that the optical element is restrained from moving to an extent that typically would adversely affect its optical characteristics or operations. However, the optical element need not have been rendered absolutely immovable, as if it had been welded or bolted to a support structure. The device also includes a base and a plurality of deformable elements coupled to the base so as to surround the optical element and retain it by applying axial and lateral forces. The degree of xe2x80x9csemi-rigidityxe2x80x9d with which the optical element is held is related to the flexibility of the deformable elements. The base and the deformable elements are formed from a single piece of material.
Yet a further embodiment is a scanner that includes a support structure, an optical element, and a device for attaching the optical element to the structure in a semi-rigid manner. The device includes a base and a plurality of deformable elements coupled to the base so as to surround the optical element and retain it by applying axial and lateral forces. The base and deformable elements are formed from a single piece of material.
In an additional embodiment, a system is described for detecting one or more biological materials. The system includes a probe array having a plurality of tags capable of fluorescing. The tags are coupled to the biological materials. Also included in the system is a scanner that has a support structure, an optical element, and a device for attaching the optical element to the support structure in a semi-rigid manner. The attachment device includes a base and a plurality of deformable elements coupled to the base so as to wholly or partially surround the optical element and retain it by applying axial and lateral forces. The base and deformable elements are formed from a single piece of material. The system further includes a radiation source that generates an excitation beam that passes through the optical element and excites the plurality of tags, causing them to fluoresce. In some implementations of this embodiment, fluorescent emissions from the plurality of tags also pass through the optical element. The probe array may be, as non-limiting examples, a spotted probe array or a synthesized probe array.
The above embodiments and implementations are not necessarily inclusive or exclusive of each other and may be combined in any manner that is non-conflicting and otherwise possible, whether they be presented in association with a same, or a different, embodiment or implementation. The description of one embodiment or implementation is not intended to be limiting with respect to other embodiments or implementations. Also, any one or more function, step, operation, or technique described elsewhere in this specification may, in alternative embodiments or implementations, be combined with any one or more function, step, operation, or technique described in the summary. Thus, the above embodiments and implementations are illustrative rather than limiting.